Infusion of weak solutions of canine brain thromboplastin into dogs over periods of a number of days indicates that depression of all the coagulation-sensitive coagulation factors may not be found. With appropriate dosages hyperfibrinogenemia can be produced. Thromboplastin, thrombin and Arvin (Malayan pit viper venom procoagulant), in various concentrations, will be given intravenously to mongrel dogs in an attempt to establish a variety of steady state chronic intravascular coagulation-fibrinolysis (ICF) patterns. Radiofibrinogen and labeled platelets will then be used to measure turnover rates during these various steady-state conditions. Interference with these ICF states by Warfarin sodium, epsilon aminocaproic acid and heparin will then be out. Finally, the procoagulant materials will be injected directly into the vasculature supplying specific organs (renal artery, portal vein) to see the effect on the target organ and on the generalized ICF pattern. The goal is to simulate chronic ICF states in man and to evaluate conventional therapeutic agents in their control.